Currently, in order to solve the problem of mixing two or more products, be they liquid, solid or gaseous, contained in confined volumes, use is made of a third confined "containment" volume with dimensions such that it contains the confined volumes to be mixed. The "containment" volume has means, such as half pressure chambers or sheaths, connected in a hermetically sealed manner and penetrating inside the confined containment volume, which allows the operator to intervene from the outside in order to manipulate, under absolutely sterile conditions, the confined volumes contained therein. After introducing the confined volumes to be manipulated inside the containment volume, and after the latter has been sealed or hermetically closed, it is necessary to perform sterilization or a particle check of the internal space of the containment volume and of the external walls of the confined volumes to be manipulated. This operation may take as long as a few hours, after which the operator can manipulate the confined volumes inside the containment space.
As can be seen, it is a complex, laborious, long and costly operation which requires special equipment.